1. Field of the Invention
The present invention relates to a hard disk drive. More particularly, the present invention relates to a head slider which includes the read/write head of the hard disk drive, and to a method of controlling the height at which the head slider floats over a data storage disk during a read/write operation.
2. Description of the Related Art
A hard disk drive (HDD) is used to store and retrieve data in computers, MPEG layer 3 (MP3) players, mobile phones, etc. To this end, a hard disk drive employs a disk, and a magnetic (read/write) head to read data recorded on the disk (so that the data can be played back) or to write new data onto the disk. The read/write head is part of a head slider that is kept floating a predetermined distance from the disk during the operation of a hard disk drive.
The height at which the head slider floats above the disk depends on the dynamic lift exerted on the head slider by air flowing over the surface of the head slider that faces the disk, and the elasticity of a suspension that supports the head slider. The dynamic lift is largely affected by the shape of the surface of the head slider that faces the disk, and by the physical properties of the airflow created between the head slider and the disk. Environmental conditions within the hard disk drive affect the physical properties of the airflow and hence, affect the dynamic lift exerted on the head slider. These environmental conditions include temperature, humidity, and air density (altitude).
The height at which the head slide floats above the disk when optimized minimizes data read/write errors and the possibility of head-disk interference (HDI). However, changes in the environmental conditions in which a hard disk drive is disposed (i.e., changes in temperature, humidity, and air density) may cause the head slider to float at less than an optimal distance from the surface of the disk. Accordingly, changes in environmental conditions can cause the hard disk drive to improperly read/write date from/onto the disk, and can also cause the magnetic head and disk to collide (HDI) with such force that the head and/or the disk becomes damaged.